Head for polishing stone



(N0 Model.) 2 Sheets-Sheet 1.

.J. KLAR. HEAD FOR POLISHING STONE.

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No. 451,327. Patented Apr. 28, 1891.

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' kUNITED STATES PATENT Ormea eIOHN KLAR, OF VESTFIELD, MASSACHUSETTS.

HEAD FOR POLISHING STONE.

SPECIFICATION forming part of Letters Patent No. 451,327, dated April28, 1891.

Application filed July 5, 1890. Serial No. 357,890. (No model.)

To @ZZ whom t may concern:

Beit known that I, JOHN KLAR, a citizen of the United States of America,residing at lVestfield, in the county of Hampden and State ofMassachusetts, have invented certain new and useful Improvements inHeads for Polishing Stone, of which the following is a specification,reference being had therein to the accompanying drawings.

My invention relates to a head for polishing stone or other material,especially granite, and has for its object apolishing or grinding` headsimple and durable of construction, capable of attachment to anypolishing-machine, and which will wear equally and evenly on its entirecontact-surface.

In the drawings, Figure 1 is a plan view of the head. Fig. 2 isasectionthrough the line a: of Fig. 1. Fig. 3 is a plan view showingrubbing-surfaces essentially rectangular in form. Fig. 4 is a plan viewof a solid polishing-head.

Similar figures of reference indicate corresponding parts.

The polishing-head is a series of rubbingsurfaces which consist ofspaced concentric rings or bands of any desired number, but

for illustration numbered in the drawings herein 1 2 3 4E, preferably ofmetal and cast integral with or rigidly secured to the upper metalliccross-bar 5, (shown in section in Fig. 2,) which serves to properlyspace and also brace and strengthen the rings or bands, and which issusceptible of being attached to any polishingmachine. The cross -bar isindicated in dotted lines in the drawings and marked 5. The rings orbands may be of any desired contour. They are shown in circular form inFig. 1 of the drawings, and essentially rectangular in Fig. 3, marked inthe latter a, o, c, and d. The attachment of the rubbing-surfaces to thecross-bar are essentially the same in my present device as in Patent No.416,4[62

Experience has shown that the outer rings or bands in a polishing-headas at present constructed wear much more rapidly than the inner, and intime only the inner surface of the head contacts with the substance tobe polished. This increased wear is mainly, if not wholly, due'to thegreater space traversed by the periphery of the outer rings or bands orouter edge thereof and consequent increased speed and friction at thatpoint over a point ator near the center, such friction decreasing as thecenter is approached, resultingin a decrease of wear of heads toward thecenter as at present constructed and consequent inequality of thepolishing-surface. I overcome the above-described difculty by arrangingor constructing the rings or bands in either of the three followingways: first, by making the outer rings orbands of greater width than theinner, graduating the width from the inner ring 1 to the outer ring orband et, so that the increased width of the outermost ring or band overthe innermost and each interior ring or band will be'ara just proportionto the friction to whicheach ring or band by its position outwardly fromthe center is subject-ed; second, by decreasing the space between therings or bands from the innermost ring or band 1 to the outermost ringor band 4, the spaces being decreased by regular gradations,thuspresenting a greatercontact of polishing-surface on the outer portion ofthe head than on the inner, such surface decreasing in regulargradations from the outer edge inwardly; third, by making the outerrings or bands of harder metal or substance than the inner, graduatingthe degree of hardness increasinmfrom the inner ring or band outwardlyby regular gradations throughout the rings from 1 to 4,so that each partwill equally resist the friction to which it is subjected by itsposition.

It is not practicable to indicate Vin either arrangement or constructionof the rings or bands herein described the exact width of the outer ringor band or its exact degree of hardness with reference to those inward,nor the exact gradation of decreasing space from the innermost ring orband to the outermost. That depends upon the material of which the ringsor bands are constructed and the number thereof. lt is plain the sameresult may measurably be attained by constructing the polishing-headsolid and graduating the hardness of the metal, increasing from centerto outer edge; but it is preferable to form it of rings or bandsgraduated in width, space, or hardness, as herein fully described.

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Having; described my invention, what I claim and desire to secure byLetters Patent, is

1. A polishing-head consisting of rubbingsurfaces rigidly attached to across-bar, the

.said rubbing-surfaces being,` of graduated Width, increasing by regulargradations from the innermost to the outermost rubbing-sur: face, as andfor the purposes described.

2. A polishing-head consisting of rubbingsurfaces rigidly attached to across-bar, said rubbing-surfacesbeing graduated in their separatingdistances, decreasing by regular `egradaiions from the innermostrubbing-sur-

